Current TVs can receive signals from a variety of input types, such as DVD, cable, MPEG, RF, VCD, etc. The signal from each input type has generally different signal characteristics. The TV picture quality of each input type is generally optimized with a different TV input setting, this TV input setting determining how the TV tuner treats the signal.
When a user switches from an input type with an optimized picture quality to a different input type, the picture quality diminishes unless the TV input setting is also changed.
For example, if the input type is a DVD, the TV input setting should be set to a high frequency response. If the input type is switched to cable, the high frequency response TV input setting causes the noise level to be heightened, resulting in a noisy picture quality.
Alternatively, if the input type is cable, the TV input setting should be set to a lower frequency response, or should employ noise reduction techniques. If the input type is then switched to DVD, the lower frequency response TV input setting causes the DVD picture quality to lose detail and become “soft”.
The following table summarizes certain of the preferred settings for various signal sources:
NoiseFrequency responseVCRHighLowDVDLowMidHDLowHigh
Current systems employ TV input settings that can be manually changed by the user.
Many users have difficulty operating these systems. In addition, they primarily serve to merely identify which of several physical TV input connectors should be used as a signal source. As such, no special signal conditioning is employed.
Various methods have been developed that enable the system to change the input setting based on certain detected signal characteristics, such as signal strength. These methods are generally cumbersome and fail to work well for all systems, in part because different types of signal overlap in various characteristics, creating ambiguous signal conditioning situations.